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(11) | EP 3 194 453 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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FRACTIONATOR FOR SEPARATING SOLUBILIZED RUBBER FROM A CO-SOLVENT BASED MISCELLA AND RELATED PROCESSES FRAKTIONIERER ZUR TRENNUNG VON SOLUBILISIERTEM KAUTSCHUK AUS CO-LÖSUNGSMITTELBASIERTER MISCELLA UND ZUGEHÖRIGE VERFAHREN FRACTIONNATEUR POUR SÉPARER DU CAOUTCHOUC SOLUBILISÉ D'UN MISCELLA À BASE DE CO-SOLVANT ET PROCÉDÉS ASSOCIÉS |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
FIELD
[0001] The present disclosure relates to a fractionator and processes that utilize the fractionator. More particularly, the present disclosure relates to a fractionator for separating solubilized rubber from a co-solvent based miscella and related processes.
BACKGROUND
[0002] Despite current technologies for producing synthetic rubber, natural rubber from sources such as the Hevea plant or tree (also called Hevea brasiliensis or a rubber tree) is still considered to possess certain superior properties as compared to synthetic rubber. A number of natural rubber sources such as Hevea brasiliensis, Ficus elastic (India rubber tree) and Cryptostegia grandiflora (Madagascar rubbervine) produce natural rubber in the form of a sap where the rubber is suspended in an aqueous solution that flows freely and can be recovered by tapping of the plant. Various non-Hevea plants are also known to contain natural rubber, but their rubber is stored within the individual cells of the plant (e.g., stems, roots, leaves) and cannot be accessed by tapping but can only be accessed by breaking down the cell walls by physical or other means. When rubber from within the cells of these non-Hevea plants is accessed, additional processing is required to separate the rubber from the various other materials. In certain processes for recovering rubber from non-Hevea plants, a miscella containing solubilized rubber and solubilized resin is produced, which is then processed to recover the rubber.
SUMMARY
[0003] Provided herein is a fractionator for separating solubilized rubber from a co-solvent based miscella. Also provided is a process for separating solubilized rubber from a co-solvent based miscella using the fractionator.
[0004] In a first embodiment, a fractionator for separating solubilized rubber from a co-solvent based miscella is provided. The fractionator comprises a primary vessel. The primary vessel comprises an upper portion and a lower portion, and a feed inlet for feeding a co-solvent based miscella into the primary vessel.
When fed into the primary vessel the co-solvent based miscella separates to form (i) a non-polar solvent viscous rubber phase in the lower portion of the primary vessel and (ii) a polar solvent solubilized resin phase above the non-polar solvent viscous rubber phase in the upper portion of the primary vessel. In addition, the primary vessel comprises a side outlet for removing the polar solvent solubilized resin phase from the upper portion of the primary vessel. The primary vessel also comprises an overflow vessel having an inlet and an outlet, wherein the overflow vessel inlet is fluidly connected to the side outlet such that the polar solvent solubilized resin phase flows through the side outlet into the overflow vessel and is removed through the overflow vessel outlet. The primary vessel also comprises a bottom outlet for removing the non-polar solvent viscous rubber phase from the primary vessel. The fractionator of the first embodiment can also be understood as comprising: a primary vessel comprising (a) a feed inlet suitable for feeding a co-solvent based miscella into the primary vessel; (b) a lower portion within the primary vessel (suitable for containing a non-polar solvent viscous rubber phase); (c) an upper portion (suitable for containing a polar solvent solubilized resin phase); (d) a side outlet suitable for removing material from the upper portion of the primary vessel (i.e., suitable for removing the polar solvent solubilized resin phase from the primary vessel); and (e) a bottom outlet suitable for removing material from the lower portion of the primary vessel (i.e., suitable for removing the non-polar solvent viscous rubber phase from the primary vessel).
[0005] In a second embodiment, a process for separating solubilized rubber from a co-solvent based miscella is provided. The process comprises providing an initial co-solvent based miscella comprising at least one polar solvent, at least one non-polar solvent, solubilized rubber, and solubilized resin, and using a fractionation system comprising multiple fractionators in series to separate the initial co-solvent based miscella into at least two phases. The multiple fractionators include a first fractionator, one or more intermediate fractionators, and a final fractionator. Each fractionator comprises a primary vessel having a (i) feed inlet, (ii) a side outlet, (iii) a bottom outlet, and (iv) an internal weir between the interior of the primary vessel and the side outlet or an overflow vessel external to the primary vessel and fluidly connected to the side outlet.
[0006] According to the processes of the second embodiment, the initial co-solvent based miscella is fed into the first fractionator primary vessel through the first fractionator primary vessel feed inlet, and the initial co-solvent based miscella separates to form (i) a first non-polar viscous rubber phase in a lower portion of the first fractionator primary vessel and (ii) a first polar solvent solubilized resin phase above the first non-polar viscous rubber phase. A first vapor blanket is maintained above the first polar solvent solubilized resin phase in an upper portion of the first fractionator primary vessel. At least a portion of the first polar solvent solubilized resin phase is allowed to flow over the internal weir of the first fractionator or into the overflow vessel of the first fractionator for removal from the first fractionator primary vessel through the side outlet. In addition, the first non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the first fractionator primary vessel and into an intermediate fractionator. Additional polar solvent and optionally additional non-polar solvent is added to the intermediate fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the first fractionator primary vessel and the mixture is allowed to separate into (i) an intermediate non-polar solvent viscous rubber phase in a lower portion of the intermediate fractionator primary vessel and (ii) an intermediate polar solvent solubilized resin phase above the intermediate non-polar solvent viscous rubber phase. An intermediate vapor blanket is maintained above the intermediate polar solvent solubilized resin phase in an upper portion of the intermediate fractionator primary vessel. At least a portion of the intermediate polar solvent solubilized resin phase is allowed to flow over the internal weir of the intermediate fractionator or into the overflow vessel of the intermediate fractionator for removal from the intermediate fractionator primary vessel through the side outlet. The intermediate non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the intermediate fractionator primary vessel and into the final fractionator. Additional polar solvent and optionally additional non-polar solvent is added to the final fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the intermediate fractionator primary vessel and the mixture is allowed to separate into (i) a final non-polar solvent viscous rubber phase in a lower portion of the final fractionator primary vessel and (ii) a final polar solvent solubilized resin phase above the final non-polar solvent viscous rubber phase. A final vapor blanket is maintained above the final polar solvent solubilized resin phase in an upper portion of the final fractionator primary vessel. At least a portion of the final polar solvent solubilized resin phase is allowed to flow over the internal weir of the final fractionator or into the overflow vessel of the final fractionator for removal from the final fractionator primary vessel. The final non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the final fractionator primary vessel, thereby providing a separated solubilized rubber phase with reduced resin and polar solvent content as compared to the initial co-solvent based miscella.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007]
FIG. 1 is a partial cutaway view of an embodiment of a fractionator with an overflow vessel.
FIG. 2 is a partial cutaway view of an embodiment of a fractionator with an internal weir.
FIG. 3 is a partial cutaway view of an embodiment of a fractionator with an internal weir.
FIG. 4 is a schematic diagram of an embodiment of multiple fractionators connected in series.
FIG. 5 is a schematic diagram of an embodiment of multiple fractionators connected in series.
FIG. 6 is a schematic diagram of an embodiment of a process for separating solubilized rubber from a co-solvent based miscella.
DETAILED DESCRIPTION
[0008] Provided herein is a fractionator for separating solubilized rubber from a co-solvent based miscella. Also provided is a process for separating solubilized rubber from a co-solvent based miscella that uses multiple fractionators. For ease of description in certain sections, the fractionator and the process are described as embodiments; the use of this terminology is for ease of description only and should not be interpreted as limiting.
Definitions
[0009] The terminology as set forth herein is for description of the embodiments only and should not be construed as limiting the invention as a whole.
[0010] As used herein, the term "non-Hevea plant" is intended to encompass plants that contain natural rubber within the individual cells of the plant.
[0011] As used herein the term "resin" means the naturally occurring non-rubber chemical entities present in a co-solvent based miscella produced from a non-Hevea plant, including but not limited to resins (such as terpenes), fatty acids, proteins, and inorganic materials.
Details
[0012] In a first embodiment, a fractionator for separating solubilized rubber from a co-solvent based miscella is provided. The fractionator comprises a primary vessel. The primary vessel comprises an upper portion and a lower portion, and a feed inlet for feeding a co-solvent based miscella into the primary vessel. When fed into the primary vessel the co-solvent based miscella separates to form two phases, (i) a non-polar solvent viscous rubber phase in the lower portion of the primary vessel and (ii) a polar solvent solubilized resin phase above the non-polar solvent viscous rubber phase. In addition, the primary vessel comprises a side outlet for removing at least a portion of the polar solvent solubilized resin phase from the upper portion of the primary vessel. The primary vessel also comprises an overflow vessel having an inlet and an outlet, wherein the overflow vessel inlet is fluidly connected to the side outlet such that the polar solvent solubilized resin phase flows through the side outlet into the overflow vessel and is removed through the overflow vessel outlet. In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase. The primary vessel also comprises a bottom outlet for removing the non-polar solvent viscous rubber phase from the primary vessel.
[0013] In a second embodiment, a process for separating solubilized rubber from a co-solvent based miscella is provided. The process comprises providing an initial co-solvent based miscella comprising at least one polar solvent, at least one non-polar solvent, solubilized rubber, and solubilized resin, and using a fractionation system comprising multiple fractionators in series to separate the initial co-solvent based miscella into at least two phases. The multiple fractionators include a first fractionator, one or more intermediate fractionators, and a final fractionator. Each fractionator comprises a primary vessel having (i) a feed inlet, (ii) a side outlet, (iii) a bottom outlet, and (iv) an internal weir between the interior of the primary vessel and the side outlet or an overflow vessel external to the primary vessel and fluidly connected to the side outlet.
[0014] According to the process of the second embodiment, the initial co-solvent based miscella is fed into the first fractionator primary vessel through the first fractionator primary vessel feed inlet, and the initial co-solvent based miscella separates to form (i) a first non-polar viscous rubber phase in a lower portion of the first fractionator primary vessel and (ii) a first polar solvent solubilized resin phase above the first non-polar viscous rubber phase. A first vapor blanket is maintained above the first polar solvent solubilized resin phase in an upper portion of the first fractionator primary vessel. At least a portion of the first polar solvent solubilized resin phase is allowed to flow over the internal weir of the first fractionator or into the overflow vessel of the first fractionator for removal from the first fractionator primary vessel through the side outlet. In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase. In addition, the first non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the first fractionator primary vessel and into an intermediate fractionator. Additional polar solvent and optionally additional non-polar solvent (any of which may be the same or different than the at least one polar solvent and the at least one non-polar organic solvent contained in the initial co-solvent based miscella) is added to the intermediate fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the first fractionator primary vessel and the mixture is allowed to separate into (i) an intermediate non-polar solvent viscous rubber phase in a lower portion of the intermediate fractionator primary vessel and (ii) an intermediate polar solvent solubilized resin phase above the intermediate non-polar solvent viscous rubber phase. An intermediate vapor blanket is maintained above the intermediate polar solvent solubilized resin phase in an upper portion of the intermediate fractionator primary vessel. At least a portion of the intermediate polar solvent solubilized resin phase is allowed to flow over the internal weir of the intermediate fractionator or into the overflow vessel of the intermediate fractionator for removal from the intermediate fractionator primary vessel through the side outlet. The intermediate non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the intermediate fractionator primary vessel and into the final fractionator. Additional polar solvent and optionally additional non-polar solvent (any of which may be the same or different than the at least one polar solvent and the at least one non-polar organic solvent contained in the initial co-solvent based miscella) is added to the final fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the intermediate fractionator primary vessel and the mixture is allowed to separate into (i) a final non-polar solvent viscous rubber phase in a lower portion of the final fractionator primary vessel and (ii) a final polar solvent solubilized resin phase above the final non-polar solvent viscous rubber phase. A final vapor blanket is maintained above the final polar solvent solubilized resin phase in an upper portion of the final fractionator primary vessel. In certain embodiments, the vapor blanket comprises air or nitrogen gas. At least a portion of the final polar solvent solubilized resin phase is allowed to flow over the internal weir of the final fractionator or into the overflow vessel of the final fractionator for removal from the final fractionator primary vessel. The final non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the final fractionator primary vessel, thereby providing a separated solubilized rubber phase with reduced resin and polar solvent content as compared to the initial co-solvent based miscella.
The Fractionator
[0015] Referring now to FIG. 1, a partial cutaway view of a fractionator (100) according to the first embodiment is shown. The fractionator (100) is useful for separating solubilized rubber from a co-solvent based miscella. As seen in FIG. 1, the fractionator (100) comprises a primary vessel (110). In certain embodiments, the primary vessel (110) has a cone-shaped lower portion. The primary vessel (110) comprises a feed inlet (120) for feeding a co-solvent based miscella into the primary vessel (110). When fed into the primary vessel (110) the co-solvent based miscella separates to form (i) a non-polar solvent viscous rubber phase (20) in a lower portion of the primary vessel (110) and (ii) a polar solvent solubilized resin phase (40) above the non-polar solvent viscous rubber phase. The line of separation between the non-polar solvent viscous rubber phase (20) and the polar solvent solubilized resin phase (40) is also referred to herein as the phase interface level. It should be understood that the phase interface level may vary in height during operation of the fractionator. As well, the relative volume of the polar solvent solubilized resin phase and the non-polar solvent viscous rubber phase during operation, may vary depending upon the respective polar and non-polar solvents utilized, the size of the fractionator and the desired residence time within the fractionator. In addition, the primary vessel (110) comprises a side outlet (130) for removing the polar solvent solubilized resin phase (40) from the primary vessel (110). The primary vessel (110) also comprises a bottom outlet (140) for removing the non-polar solvent viscous rubber phase (20) from the primary vessel (110).
[0016] In certain embodiments, the primary vessel (100) of the fractionator (100) comprises additional inlets and outlets for feeding and removing additional components. For example, the primary vessel (110) may comprise a gas inlet (170) and a gas outlet, as seen in FIGS. 1-3. The gas inlet (170) may be used to add a vapor blanket (60) to the fractionator (100), for example, above the polar solvent solubilized resin phase (40). Similarly, the gas outlet (180) may be used to purge or vent vapor from the fractionator (100). The optional gas inlet may also be understood as suitable for adding a vapor blanket to the fractionator (e.g., within the upper portion of the primary vessel). The optional gas outlet may also be understood as suitable for purging or venting vapor from the fractionator (e.g., from within the upper portion of the primary vessel).
[0017] With continued reference to FIGS. 1-3, in certain embodiments, the primary vessel (110) comprises at least one solvent inlet (190) for feeding additional solvent to the primary vessel (110). It should be understood that the at least one solvent inlet (190) may be a polar solvent inlet for adding polar solvent to the fractionator (100) or a non-polar solvent inlet for adding non-polar solvent to the fractionator (100). In certain embodiments, the primary vessel (110) comprises a polar solvent inlet for adding polar solvent to the fractionator (100) and a non-polar solvent inlet for adding non-polar solvent to the fractionator (100).
[0018] With reference now to FIG. 1, the fractionator (100) comprises an overflow vessel (160). The overflow vessel (160) has an inlet (162) and an outlet (164). The overflow vessel inlet (162) is fluidly connected to the side outlet (130) such that at least a portion of the polar solvent solubilized resin phase (40) flows through the side outlet (130) into the overflow vessel (160). The overflow vessel inlet (162) can also be understood as fluidly connected to the side outlet (130) such that at least a portion of material located within the upper portion of the primary vessel may flow through the side outlet (130) into the overflow vessel (160). Accordingly, the overflow vessel (160) assists in controlling the phase interface level in the primary vessel (110) as well as in removing the polar solvent resin phase. The polar solvent solubilized resin phase (40) that is collected in the overflow vessel (160) is removed through the overflow vessel outlet (164). In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase. The side outlet (130) and overflow vessel (160) combination improve the safety of the fractionator (100) by allowing the fractionator (100) to operate without a liquid full volume and also provide better control of the phase interface level.
[0019] Referring now to FIGS. 2 and 3, in certain embodiments, the primary vessel (110) comprises an internal weir (150). As seen in FIGS. 2 and 3, the side outlet (130) is bounded by the internal weir (150) such that the polar solvent solubilized resin phase (40) must flow over the internal weir (150) to remove the polar solvent solubilized resin phase (40) through the side outlet (130). In other words, the internal weir (150) provides an interior barrier to the side outlet (130) that must be overcome before the polar solvent solubilized resin phase (40) can be removed from the primary vessel (110) through the side outlet (130). Thus, it can be appreciated that the internal weir (150) assists in controlling the phase interface level in the primary vessel (110). The side outlet (130) and internal weir (150) combination improve the operation of the fractionator (100) by allowing the fractionator (100) to operate without a liquid full volume and by providing better control of the phase interface level.
[0020] As seen in FIG. 2, in certain embodiments, the internal weir (150) forms a wall around a portion of the circumference of an upper interior portion of the primary vessel (110). Alternatively, in certain embodiments, the internal weir (150) forms a wall around the entire circumference of an upper interior portion of the primary vessel (110), as shown in FIG. 3. In such embodiments, the feed inlet that feeds the co-solvent based miscella (or the non-polar solvent viscous rubber phase) is positioned so that it feeds material into the interior of the primary vessel and not into the internal weir. As previously mentioned, the internal weir (150) functions to separate the side outlet (130) from the interior volume of the primary vessel (110) occupied by liquid (i.e., the separated co-solvent based miscella) until the level of the polar solvent solubilized resin phase (40) overcomes the internal weir (150) to allow at least a portion of the polar solvent solubilized resin phase (40) to flow from the primary vessel (110) through the side outlet (130). In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase.
[0021] In certain embodiments, the fractionator (100) further comprises at least one additional fractionator connected in series, wherein each additional fractionator has a feed inlet that is fluidly connected to the bottom outlet of the preceding fractionator. For example, as seen in FIG. 4, a first fractionator (100) is connected in series with a second fractionator (200) and a third fractionator (300). Although FIG. 4 depicts three fractionators, it should be understood that additional fractionators may be utilized. An initial co-solvent based miscella (50) is fed into the primary vessel (110) of the first fractionator (100) through the feed inlet (120). In certain embodiments, the initial co-solvent based miscella (50) is fed through a heat exchanger (102) (heated or cooled with appropriate plant utilities (U) (e.g., hot water, cooling water)) and/or a static mixer (104) prior to being fed into the primary vessel (110) of the first fractionator (100). As seen in FIG. 4, the bottom outlet (140) of the first fractionator (100) is fluidly connected to the feed inlet (220) of the second fractionator. In certain embodiments, a bottoms pump (106) is fluidly connected to the bottom outlet (140) of the first fractionator (100) and the feed inlet (220) of the second fractionator (200) and operates to transport the non-polar solvent viscous rubber phase from the first fractionator (100) to the second fractionator (200). Similarly, the bottom outlet (240) of the second fractionator (200) is fluidly connected to the feed inlet (320) of the third fractionator (300). As seen in FIG. 4, in certain embodiments, a bottoms pump (206) is fluidly connected to the bottom outlet (240) of the second fractionator (200) and the feed inlet (320) of the third fractionator (300) and operates to transport the non-polar solvent viscous rubber phase from the second fractionator (200) to the third fractionator (300).
[0022] With continued reference to FIG. 4, in certain embodiments, each fractionator (100, 200, 300) comprises a polar solvent inlet (190, 290, 390) for adding polar solvent to the fractionator (100, 200, 300). The solubilized rubber is preferentially soluble in the non-polar solvent, and thus, as additional polar solvent is added the relative amount of polar solvent as compared to non-polar solvent is increased so as to cause the solubilized rubber to coagulate to form the non-polar solvent viscous rubber phase. Accordingly, adding additional polar solvent promotes the separation of the solubilized rubber from the solubilized resin. In certain embodiments, polar solvent may be added to a fractionator (100, 200, 300) by providing a polar solvent feed line that is fluidly connected to the feed inlet (120, 220, 320) of the fractionator (100, 200, 300). By way of example, polar solvent may be fed into the third fractionator (300) by providing a polar solvent feed line that connects into the flow stream that enters into the feed inlet (320) of the third fractionator (300).
[0023] In certain embodiments, at least one of the fractionators comprises a resin phase feed line that is fluidly connected to the preceding fractionator. For example, as seen in FIG. 4, the third fractionator (300) has a resin phase feed line (366) that is fluidly connected to the second fractionator (200), thus allowing the polar solvent solubilized resin phase of the third fractionator (300) to flow to the second fractionator (200). In certain embodiments, as seen in FIG. 4, a resin pump (308) is fluidly connected to the third fractionator (300) and the feed inlet of the (220) second fractionator and operates to transport the polar solvent solubilized resin phase from the third fractionator (300) to the second fractionator (200).
[0024] In certain embodiments, a resin pump (108) is fluidly connected to the first fractionator (100) and a resin tank and operates to transport the polar solvent solubilized resin phase from the first fractionator (100) to the resin tank via stream (70), as seen in FIG. 4. Similarly, in certain embodiments, a resin pump (208) is fluidly connected to the second fractionator (200) and a resin tank and operates to transport the polar solvent solubilized resin phase from the second fractionator (200) to the resin tank via stream (70).
[0025] In certain embodiments, the fractionator comprises at total of six fractionators connected in series. For example, as seen in FIG. 5, six fractionators (100, 200, 300, 400, 500, 600) are connected in series, wherein each fractionator after the first fractionator (100) has a feed inlet (220, 320, 420, 520, 620) that is fluidly connected to the bottom outlet (140, 240, 340, 440, 540) of the preceding fractionator. For instance, the bottom outlet (140) of the first fractionator (100) is fluidly connected to the feed inlet (220) of the second fractionator (200), the bottom outlet (240) of the second fractionator (200) is fluidly connected to the feed inlet (320) of the third fractionator (300), and so forth. As illustrated in FIG. 5, in certain embodiments, a bottoms pump (106, 206, 306, 406, 506) is fluidly connected to the bottom outlet (140, 240, 340, 440, 540) of a fractionator (100, 200, 300, 400, 500) and the feed inlet (220, 320, 420, 520, 620) of the next successive fractionator (200, 300, 400, 500, 600) and operates to transport the non-polar solvent viscous rubber phase from one fractionator (100, 200, 300, 400, 500) to the next successive fractionator (200, 300, 400, 500, 600).
[0026] With continued reference to FIG. 5, in certain embodiments, the fractionator comprises at total of six fractionators connected in series, and at least one of the intermediate fractionators further comprises a resin phase feed line that is fluidly connected to the preceding fractionator. For example, as seen in FIG. 5, the third fractionator (300) comprises a resin phase feed line (366) that is fluidly connected to the second fractionator (200), the fourth fractionator (400) comprises a resin phase feed line (466) that is fluidly connected to the third fractionator (300), and the fifth fractionator (500) comprises a resin phase feed line (566) that is fluidly connected to the fourth fractionator (400). In certain embodiments, the sixth or final fractionator (600) comprises a resin phase feed line (666) that is fluidly connected to the fifth fractionator (500), as illustrated in FIG. 5. In certain embodiments, a resin pump (308, 408, 508, 608) is fluidly connected to the fractionator (300, 400, 500, 600) and the feed inlet of the (220, 320, 420, 520) preceding fractionator and operates to transport the polar solvent solubilized resin phase from one fractionator (300, 400, 500, 600) to the preceding fractionator (200, 300, 400, 500, 600).
The Process
[0027] In accordance with the second embodiment, a process for separating solubilized rubber from a co-solvent based miscella is provided. Generally, the process may be characterized as a counter-current solvent extraction process in which solubilized rubber is separated and recovered from an initial co-solvent based miscella. In certain embodiments, the initial co-solvent based miscella comprises about 1 to about 10 weight % rubber (solubilized), about 1 to about 15 weight % resin (solubilized), and about 75 to about 98 weight % combined non-polar and polar solvents. In certain embodiments, the initial co-solvent based miscella comprises about 1 to about 6 weight % rubber (solubilized), about 2 to about 8 weight % resin (solubilized), and about 86 to about 97 weight % combined non-polar and polar solvents. During the process, the resin that is contained within the co-solvent based miscella is separated from the rubber that is also contained therein, relying upon the relatively higher solubility of the rubber in the non-polar solvent and the relatively higher solubility of the resin in the polar solvent. Accordingly, the separated solubilized rubber phase that results from the process comprises relatively less resin and polar solvent than the initial co-solvent based miscella. In certain embodiments, the separated solubilized rubber phase that results comprises 0-6 weight % resin, including about 0.5 to about 4 weight % resin (based on the total dry weight of combined resin and rubber in the separated solubilized rubber phase, i.e., with all solvent removed). In certain embodiments, the separated solubilized rubber phase that results comprises no more than about 6 weight %, no more than about 5 weight %, no more than about 4 weight %, no more than about 3 weight%, no more than about 2 weight %, or no more than about 1 weight % resin (based on the total dry weight of combined resin and rubber in the separated solubilized rubber phase, i.e., with all solvent removed).
Co-solvent based miscella
[0028] According to the process of the second embodiment disclosed herein, an initial co-solvent based miscella is provided for processing. The initial co-solvent miscella comprises at least one polar solvent, at least one non-polar solvent, solubilized rubber, and solubilized resin. In certain embodiments, the initial co-solvent based miscella that is processed in accordance with the second embodiment is produced utilizing a non-Hevea plant. Exemplary non-Hevea plants from which the initial co-solvent based miscella may be produced include, but are not limited to: Parthenium argentatum (Guayule shrub), Taraxacum Kok-Saghyz (Russian dandelion), Euphorbia lathyris (gopher plant), Parthenium incanum (mariola), Chrysothamnus nauseosus (rabbitbrush), Pedilanthus macrocarpus (candililla), Asclepias syriaca, speciosa, subulata, et al (milkweeds), Solidago altissima, graminifolia rigida, et al (goldenrods), Cacalia atripilicifolia (pale Indian plantain), Pycnanthemum incanum (mountain mint), Teucreum canadense (American germander) and Campanula Americana (tall bellflower). Other plants which produce rubber and rubber-like hydrocarbons are known, particularly among the Compositae, Euphorbiaceae, Campanulaceae, Labiatae, and Moracea families. It is contemplated that the initial co-solvent based miscella processed in accordance with the processes disclosed herein may be produced from a single type of non-Hevea plant or a mixture of more than one type of non-Hevea plant. Accordingly, in certain embodiments, the solubilized rubber of the initial co-solvent based miscella comprises non-Hevea rubber. In a preferred embodiment, the non-Hevea rubber is from guayule.
[0029] In certain embodiments, the initial co-solvent based miscella is held in a storage tank and is provided to the process by conventional means, for example, a pump.
Fractionation system
[0030] The process of the second embodiment disclosed herein use a fractionation system (1000) comprising multiple fractionators in series to separate the initial co-solvent based miscella into at least two phases. As seen in FIG. 6, the multiple fractionators include a first fractionator (100), one or more intermediate fractionators (200, 300, 400, 500), and a final fractionator (600). Although FIG. 6 shows the fractionation system (1000) as having six fractionators, it should be understood that the fractionation system (1000) may have less than six fractionators or more than six fractionators.
[0031] The individual fractionators comprising the fractionation system (1000) used in the processes disclosed herein may be configured in accordance with any of the previously described fractionators of the first embodiment, for example, the fractionators shown in FIGS. 1-5. In general, each fractionator comprising the fractionation system (1000) comprises a primary vessel having a feed inlet, a side outlet, and a bottom outlet.
[0032] In certain embodiments of the second embodiment, one or more fractionators comprising the fractionation system (1000) comprise an internal weir (150) between the interior of the primary vessel (110) and the side outlet (130), as seen in the fractionators (100) of FIGS. 2 and 3. For example, as shown in FIGS. 2 and 3, in certain embodiments of the second embodiment, the primary vessel of the fractionator (100) comprises an internal weir (150) and the side outlet (130) of the fractionator (100) is bounded by the internal weir (150) such that at least a portion of the polar solvent resin phase (40) flows over the internal weir (150) to remove the polar solvent resin phase (40) through the side outlet (130). In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase. Additionally, the internal weir (150) forms a wall around at least a portion of the circumference of an upper interior portion of the primary vessel (110).
[0033] In certain embodiments of the second embodiment, one or more fractionators comprising the fractionation system (1000) comprise an overflow vessel (160) external to the primary vessel (110) and fluidly connected to the side outlet (130), as seen in the fractionator (100) of FIG. 1. For example, as shown in FIG. 1, in certain embodiments of the second embodiment, the fractionator (100) comprises an overflow vessel (160) external to the primary vessel (110). The overflow vessel (160) has an inlet (162) and an outlet (164). The overflow vessel inlet (162) is fluidly connected to the side outlet (130) such that the polar solvent solubilized resin phase (40) flows through the side outlet (130) into the overflow vessel (160). The polar solvent solubilized resin phase (40) that is collected in the overflow vessel (160) is removed through the overflow vessel outlet (164). In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase.
[0034] As mentioned above, the multiple fractionators of the fractionation system (1000) are connected in series. In other words, the feed inlet of a fractionator is fluidly connected to a bottom outlet of the preceding fractionator. Accordingly, rubber-containing material (i.e., the non-polar solvent viscous rubber phase) is allowed to flow out of the bottom outlet of a fractionator and into the feed inlet of the next successive fractionator. In certain embodiments of the second embodiment, at least two intermediate fractionators are used and each additional intermediate fractionator is connected in series and positioned between the first fractionator and the final fractionator. For example, in certain embodiments, at least four intermediate fractionators (200, 300, 400, 500) are used, and each intermediate fractionator is connected in series and positioned between the first fractionator (100) and the final fractionator (600), as seen in FIG. 6. It can also be seen that the first fractionator (100) and the final fractionator (600) are connected in series with the intermediate fractionators (200, 300, 400, 500).
Process flow
[0035] With reference now to FIG. 6, the process flow of an embodiment of a process according to the second embodiment will be described. As seen in FIG. 6, the initial co-solvent based miscella (50) is fed into a first fractionator (100). More specifically, the initial co-solvent based miscella is fed into the first fractionator primary vessel through the first fractionator primary vessel feed inlet. In certain embodiments of the processes disclosed herein, the initial co-solvent based miscella (50) flows through a heat exchanger (102) (supplied with appropriate plant utilities (U), e.g., hot water, cooling water, steam, etc.) to control the temperature of the initial co-solvent based miscella (50) entering the first fractionator (100). In certain embodiments of the second embodiment, the temperature of the initial co-solvent based miscella (50) entering the first fractionator (100) is about 50 °F to about 120 °F (about 10 °C to about 50 °C), and preferably about 60 to about 80 °F (about 16 °C to about 27 °C). This particular temperature range of the initial co-solvent based miscella (50) promotes better downstream phase separation in the fractionators.
[0036] In certain embodiments of the second embodiment, polar solvent (80) is added to the initial co-solvent based miscella (50) prior to or after the initial co-solvent based miscella (50) is fed into the first fractionator primary vessel. For example, in certain embodiments, the polar solvent (80) is combined with the initial co-solvent based miscella (50) prior to entering the first fractionator (100), as seen in FIG. 6. In other embodiments, the polar solvent (80) is fed directly into the first fractionator (100), such as through a solvent inlet as previously mentioned. In certain embodiments, the polar solvent (80) flows through a heat exchanger (82) to control the temperature of the polar solvent (80) being added to the initial co-solvent based miscella (50). In certain embodiments, the polar solvent (80) is stored in a tank and is provided to the process by conventional means, for example, a pump.
[0037] In certain embodiments, where the polar solvent (80) is combined with the initial co-solvent based miscella (50), the combined stream flows through a static mixer (104), as seen in FIG. 6. The static mixer (104) permits gentle mixing of the combined stream of the polar solvent (80) and the initial co-solvent based miscella (50). Accordingly, the static mixer (104) avoids aggressive mixing of the combined stream of the polar solvent (80) and the initial co-solvent based miscella (50), which can lead to problems in achieving the desired phase separation in the fractionators.
[0038] After the initial co-solvent based miscella (50) is fed into the first fractionator (100), the initial co-solvent based miscella (50) separates to form (i) a first non-polar solvent viscous rubber phase in a lower portion of the first fractionator primary vessel and (ii) a first polar solvent solubilized resin phase above the first non-polar solvent viscous rubber phase. In certain embodiments, adding additional polar solvent (80) to the initial co-solvent based miscella (50) promotes the separation of the non-polar solvent viscous rubber phase from the polar solvent solubilized resin phase by causing high molecular weight solubilized rubber (preferably rubber with a molecular weight of at least 800,000 (e.g., 800,000-1,500,000), even more preferably at least 1,000,000 (e.g., 1,000,000-1,500,000)) to coagulate, thereby forming the non-polar solvent viscous rubber phase. Lower molecular weight solubilized rubber may remain in the polar solvent solubilized resin phase. The molecular weights of rubber that are referred to herein are determined by GPC, utilizing a polystyrene standard.
[0039] As previously mentioned with respect to fractionator of the first embodiment, the fractionators utilized in the fractionation system (1000) of the second embodiment are operated such that a vapor blanket is maintained above the polar solvent solubilized resin phase in an upper portion of the fractionator primary vessel. In certain embodiments, the vapor blanket comprises air or nitrogen gas. Accordingly, the fractionators are operated such that less than the total volume of the fractionator primary vessel is occupied by liquid. As previously mentioned with respect to the fractionator of the first embodiment, in certain embodiments of the second embodiment, the fractionators utilized in the fractionation system (1000) may include a gas inlet and a gas outlet. As seen in FIG. 6, in certain embodiments of the second embodiment, the fractionators may be purged or vented via vent lines (112, 212, 312, 412, 512, 612) to a common vent line header for additional processing.
[0040] In certain embodiments of the processes disclosed herein, it may be helpful to allow for some amount of residence time to allow the non-polar solvent viscous rubber phase to separate from the polar solvent solubilized resin phase in the fractionators. The particular residence time will depend upon various factors including, but not limited to, the volume of the fractionator, the flow rate, the particular polar and non-polar solvents utilized, and the rubber content of the miscella. In certain embodiments, the total residence time (i.e., combined time) within all of the fractionators used in the process is about 30 minutes to about 4 hours. With respect to the first fractionator (100), during operation at least a portion of the first polar solvent solubilized resin phase is removed from the first fractionator primary vessel. For example, in certain embodiments of the second embodiment, the first fractionator may comprise an internal weir or an overflow vessel, as previously described, for allowing removal of at least a portion of the first polar solvent solubilized resin phase. In certain embodiments of the second embodiment, the portion of the first polar solvent solubilized resin phase (161) that is removed from the first fractionator (100) is transferred to a resin tank for storage or further processing and is not conveyed to any other fractionator.
[0041] With continued reference to FIG. 6, the first non-polar solvent viscous rubber phase (111) is allowed to flow out of the bottom outlet of the first fractionator primary vessel and into an intermediate fractionator (200). Additional polar solvent, and optionally additional non-polar solvent, is added to the intermediate fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the first fractionator. In certain embodiments of the second embodiment, the additional polar solvent, and optionally additional non-polar solvent, is added directly to the intermediate fractionator (200). In certain embodiments of the second embodiment, the additional polar solvent, and optionally additional non-polar solvent, is combined with the non-polar solvent viscous rubber phase (111) and the combined stream is fed into the intermediate fractionator (200). In certain embodiments of the second embodiment, the additional polar solvent is provided by the polar solvent solubilized resin phase of the next successive fractionator. For example, as seen in FIG. 6, the polar solvent solubilized resin phase (361) removed from intermediate fractionator (300) is combined with the first non-polar solvent viscous rubber phase (111) and the combined stream is fed into intermediate fractionator (200). In certain embodiments, where the polar solvent solubilized resin phase (361) from intermediate fractionator (300) is combined with the first non-polar solvent viscous rubber phase (111), the combined stream flows through a static mixer (204) prior to entering intermediate fractionator (200), as seen in FIG. 6.
[0042] After the co-solvent based miscella mixture is fed into the intermediate fractionator (200), the mixture is allowed to separate into (i) an intermediate non-polar solvent viscous rubber phase in a lower portion of the intermediate fractionator primary vessel and (ii) an intermediate polar solvent solubilized resin phase above the intermediate non-polar solvent viscous rubber phase. As previously discussed, during operation of the intermediate fractionator an intermediate vapor blanket is maintained above the intermediate polar solvent solubilized resin phase in an upper portion of the intermediate fractionator primary vessel.
[0043] During operation of the intermediate fractionator (200) at least a portion of the intermediate polar solvent solubilized resin phase is removed from the intermediate fractionator primary vessel. For example, in certain embodiments of the second embodiment, the intermediate fractionator may comprise an internal weir or an overflow vessel, as previously described, for allowing removal of at least a portion of the intermediate polar solvent solubilized resin phase. In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase. In certain embodiments of the second embodiment, the portion of the intermediate polar solvent solubilized resin phase (261) that is removed from the first intermediate fractionator (200) is transferred to a resin tank for storage or further processing and is not conveyed to any other fractionator. Accordingly, in certain embodiments of the processes disclosed herein, the polar solvent solubilized resin phase that is removed from the first fractionator and the first intermediate fractionator is not conveyed to any other fractionator.
[0044] The operation of any additional intermediate fractionators may proceed in a manner similar to the operation of the first fractionator (100) and the intermediate fractionator (200) as described above. The process according to the second embodiment as illustrated in FIG. 6 includes four intermediate fractionators (200, 300, 400, 500), which are connected in series with the first fractionator (100) and the final fractionator (600). The separation of the non-polar solvent viscous rubber phase from the polar solvent solubilized resin phase that occurs in the intermediate fractionators (300, 400, 500) proceeds as described with respect to intermediate fractionator (200). In addition, the non-polar solvent viscous rubber phase is allowed to flow out of the bottom outlet of the fractionator primary vessel and into the next successive fractionator. However, in certain embodiments of the second embodiment, such as the embodiment shown in FIG. 6, where the fractionation system comprises at least four intermediate fractionators, the polar solvent solubilized resin phase that is removed from at least three of the intermediate fractionators is fluidly conveyed to the preceding intermediate fractionator. For example, the polar solvent solubilized resin phase removed from intermediate fractionator (300) is fluidly conveyed via stream (361) to intermediate fractionator (200), the polar solvent solubilized resin phase removed from intermediate fractionator (400) is fluidly conveyed via stream (461) to intermediate fractionator (300), and the polar solvent solubilized resin phase removed from intermediate fractionator (500) is fluidly conveyed via stream (561) to intermediate fractionator (400).
[0045] As seen in FIG. 6, in certain embodiments, the polar solvent solubilized resin phase stream from an intermediate fractionator is combined with the non-polar solvent viscous rubber phase stream exiting the bottom outlet of the second preceding fractionator. For example, the polar solvent solubilized resin phase stream (361) from intermediate fractionator (300) is combined with the non-polar solvent viscous rubber phase stream (111) exiting the bottom outlet of the first fractionator (100) and is fed to intermediate fractionator (200), as seen in FIG. 6. In certain embodiments, where the polar solvent solubilized resin phase stream (361) from intermediate fractionator (300) is combined with the non-polar solvent viscous rubber phase stream (111), the combined stream flows through a static mixer (204) prior to entering intermediate fractionator (200). Similarly, in certain embodiments, the polar solvent solubilized resin phase stream (461) from intermediate fractionator (400) is combined with the non-polar solvent viscous rubber phase stream (211) exiting the bottom outlet of intermediate fractionator (200) and is fed to intermediate fractionator (300). In certain embodiments, where the polar solvent solubilized resin phase stream (461) from intermediate fractionator (400) is combined with the non-polar solvent viscous rubber phase stream (211), the combined stream flows through a static mixer (304) prior to entering intermediate fractionator (300). In certain embodiments, the polar solvent solubilized resin phase stream (561) from intermediate fractionator (500) is combined with the non-polar solvent viscous rubber phase stream (311) exiting the bottom outlet of intermediate fractionator (300) and is fed to intermediate fractionator (400). In certain embodiments, where the polar solvent solubilized resin phase stream (561) from intermediate fractionator (500) is combined with the non-polar solvent viscous rubber phase stream (311), the combined stream flows through a static mixer (404) prior to entering intermediate fractionator (400), as seen in FIG. 6. As previously mentioned, the polar solvent solubilized resin phase provides additional polar solvent to promote the separation of the non-polar solvent viscous rubber phase from the polar solvent solubilized resin phase in the fractionators.
[0046] With continued reference to FIG. 6, in certain embodiments, the intermediate non-polar solvent viscous rubber phase (411) of intermediate fractionator (400) is allowed to flow out of the bottom outlet of the intermediate fractionator primary vessel and into intermediate fractionator (500). As previously mentioned, additional polar solvent, and optionally additional non-polar solvent, may be added to the intermediate fractionator primary vessel to form a co-solvent based miscella mixture. Separation of the co-solvent based miscella mixture proceeds as previously described. In certain embodiments of the second embodiment, additional polar solvent and additional non-polar solvent (90) are added directly to the intermediate fractionator (500). In certain embodiments of the second embodiment, the additional polar solvent and additional non-polar solvent (90) is combined with the non-polar solvent viscous rubber phase (411) and the combined stream is fed into the intermediate fractionator (500). In certain embodiments, the additional non-polar solvent (90) flows through a heat exchanger (92) (supplied with appropriate plant utilities (U), e.g., hot water, cooling water, steam, etc.) to control the temperature of the non-polar solvent (90) being added to the process. In certain embodiments of the second embodiment, the polar solvent solubilized resin phase (661) that is removed from the final fractionator is fluidly conveyed to the preceding intermediate fractionator (500) to provide additional polar solvent to the intermediate fractionator (500). For example, in certain embodiments, as seen in FIG. 6, the polar solvent solubilized resin phase (661) removed from final fractionator (600) is combined with the non-polar solvent stream (90) and intermediate non-polar solvent viscous rubber phase stream (411) and the combined stream is fed into intermediate fractionator (500). In certain embodiments, where the polar solvent solubilized resin phase (661) from final fractionator (600) is combined with the non-polar solvent stream (90) and intermediate non-polar solvent viscous rubber phase (411), the combined stream flows through a static mixer (504) prior to entering intermediate fractionator (500), as seen in FIG. 6. In certain embodiments, the addition of polar solvent and non-polar solvent serves to promote separation of the non-polar solvent viscous rubber phase and the polar solvent solubilized resin phase.
[0047] As seen in FIG. 6, the intermediate non-polar solvent viscous rubber phase (511) is allowed to flow out of the bottom outlet of the intermediate fractionator primary vessel (i.e., the last intermediate fractionator (500)) and into the final fractionator (600). Additional polar solvent (80), and optionally additional non-polar solvent (90), is added to the final fractionator primary vessel to form a co-solvent based miscella mixture. In certain embodiments of the second embodiment, the additional polar solvent (80), and optionally additional non-polar solvent (90), is added directly to the final fractionator (600). In certain embodiments of the second embodiment, the additional polar solvent (80), and optionally additional non-polar solvent (90), is combined with the non-polar solvent viscous rubber phase (511) and the combined stream is fed into the final fractionator (600). In certain embodiments of the second embodiment, the additional polar solvent (80) is provided from a polar solvent storage tank and may flow through a heat exchanger (82) to control the temperature of the polar solvent (80) being added to the final fractionator (600). In certain embodiments of the second embodiment, the additional non-polar solvent (90) is provided from a non-polar solvent storage tank and may flow through a heat exchanger (92) to control the temperature of the non-polar solvent (90) being added to the final fractionator. In certain embodiments, where the additional polar solvent (80), the additional non-polar solvent (90), and the intermediate non-polar solvent viscous rubber phase (511) are combined, the combined stream flows through a static mixer (604) prior to entering the final fractionator (600), as seen in FIG. 6.
[0048] In certain embodiments of the second embodiment, the relative amount of polar solvent (80) added to the final fractionator (600) is greater than the amount of non-polar solvent added to the final fractionator (600). By adding relatively more polar solvent (80) than non-polar solvent (90), the concentration of solubilized rubber in the non-polar solvent viscous rubber phase (611) increases, which reduces the amount of non-polar solvent that will have to be removed from the non-polar solvent viscous rubber phase and also causes the rubber to drop out of solution.
[0049] Separation of the co-solvent based miscella mixture in the final fractionator (600) proceeds in the same manner as previously described with respect to the other fractionators. For example, after the co-solvent based miscella mixture is fed into the final fractionator (600), the mixture is allowed to separate into (i) a final non-polar solvent viscous rubber phase in a lower portion of the final fractionator primary vessel and (ii) a final polar solvent solubilized resin phase above the final non-polar solvent viscous rubber phase. During operation of the final fractionator a final vapor blanket is maintained above the final polar solvent solubilized resin phase in an upper portion of the final fractionator primary vessel.
[0050] During operation of the final fractionator (600) at least a portion of the final polar solvent solubilized resin phase is removed from the final fractionator primary vessel. For example, in certain embodiments of the second embodiment, the final fractionator may comprise an internal weir or an overflow vessel, as previously described, for allowing removal of at least a portion of the final polar solvent solubilized resin phase. In certain embodiments, at least a majority of the polar solvent solubilized resin phase, and preferably substantially all of the polar solvent solubilized resin phase (i.e., at least 90% by volume) is removed in this manner. It should be understood that a relatively minor amount of polar solvent and solubilized resin may remain associated with the non-polar solvent viscous rubber phase. As previously described, in certain embodiments of the second embodiment, the portion of the final polar solvent solubilized resin phase (661) that is removed from the final fractionator (600) is transferred to the preceding fractionator (500).
[0051] In accordance with the second embodiment, the final non-polar solvent viscous rubber phase (611) is allowed to flow out of the bottom outlet of the final fractionator primary vessel, thereby providing a separated solubilized rubber phase with reduced resin and polar solvent content as compared to the initial co-solvent based miscella. In certain embodiments, the final non-polar solvent viscous rubber phase (611) is transferred to a storage tank where it can undergo additional processing to provide a purified rubber product.
[0052] The process according to the second embodiment as described herein is preferably conducted on a continuous basis. For example, a continuous stream of initial co-solvent based miscella (50) may be fed into the fractionation system (1000) and a continuous stream of final non-polar solvent viscous rubber phase (611) may exit the fractionation system (1000).
Solvents
[0053] In any of the embodiments of the processes disclosed herein, the solvents contained within the co-solvent based miscella and any additional solvents (polar solvent, non-polar solvent, or a combination thereof) added elsewhere to the process may be the same or different (i.e., overall one non-polar solvent may be utilized and overall one polar solvent may be utilized, or alternatively more than one of each maybe be utilized.). Preferably, all non-polar solvent utilized within the process are the same and all polar solvent utilized within the process are the same.
[0054] In any of the foregoing embodiments of the processes disclosed herein, the at least one polar solvent of the co-solvent based miscella and any additional polar solvent added elsewhere to the process may be selected from the group consisting of alcohols having 1 to 8 carbon atoms (e.g., ethanol, isopropanol, ethanol and the like); ethers and esters having from 2 to 8 carbon atoms; cyclic ethers having from 4 to 8 carbon atoms; and ketones having from 3 to 8 carbon atoms (e.g., acetone, methyl ethyl ketone and the like); and combinations thereof. In certain preferred embodiments of the processes disclosed herein, the at least one non-polar solvent of the co-solvent based miscella and any additional non-polar solvent added elsewhere in the process are each hexane or cyclohexane, and the at least one polar solvent of the co-solvent based miscella and any additional polar solvent added elsewhere in the process is optionally acetone. Other polar solvents (individually or in combination) may be used in embodiments of the processes disclosed herein as long as the polar solvent preferentially solvates a portion of non-rubber extractables (e.g., resins) and acts (at a certain concentration) to coagulate natural rubber. In any of the embodiments of the processes disclosed herein, mixtures of two or more polar solvents may be utilized.
[0055] In any of the foregoing embodiments of the processes described herein, the at least one non-polar solvent that is contained in the co-solvent based miscella and any additional non-polar solvent added elsewhere in the process may be selected from the group consisting of alkanes having from 4 to 9 carbon atoms (e.g., pentane, hexane, heptanes, nonane and the like); cycloalkanes and alkyl cycloalkanes having from 5 to 10 carbon atoms (e.g., cyclohexane, cyclopentane and the like); aromatics and alkyl substituted aromatics having from 6 to 12 carbon atoms (e.g., benzene, toluene, xylene and the like); and combinations thereof. In certain preferred embodiments according of the processes disclosed herein, the at least one polar solvent of the co-solvent based miscella and any additional polar solvent added to the process is acetone, and the at least one non-polar solvent of the co-solvent based miscella and any additional non-polar solvent added to the process are optionally hexane or cyclohexane. Other non-polar solvents (individually or in combination) may be used in embodiments of the processes disclosed herein as long as the non-polar solvent preferentially solvates natural rubber. In any of the embodiments of the processes disclosed herein, mixtures of two or more non-polar solvents may be utilized.
[0056] To the extent that the term "includes" or "including" is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term "comprising" as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term "or" is employed (e.g., A or B) it is intended to mean "A or B or both." When the applicants intend to indicate "only A or B but not both" then the term "only A or B but not both" will be employed. Thus, use of the term "or" herein is the inclusive, and not the exclusive use. See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent that the terms "in" or "into" are used in the specification or the claims, it is intended to additionally mean "on" or "onto." Furthermore, to the extent the term "connect" is used in the specification or claims, it is intended to mean not only "directly connected to," but also "indirectly connected to" such as connected through another component or components.
a primary vessel comprising:
an upper portion and a lower portion;
a feed inlet for feeding a co-solvent based miscella into the primary vessel, wherein the co-solvent based miscella separates to form (i) a non-polar solvent viscous rubber phase in the lower portion of the primary vessel and (ii) a polar solvent solubilized resin phase above the non-polar solvent viscous rubber phase in the upper portion of the primary vessel;
a side outlet for removing the polar solvent solubilized resin phase from the upper portion of the primary vessel;
an overflow vessel having an inlet and an outlet, wherein the overflow vessel inlet is fluidly connected to the side outlet such that the polar solvent solubilized resin phase flows through the side outlet into the overflow vessel and is removed through the overflow vessel outlet; and
a bottom outlet for removing the non-polar solvent viscous rubber phase from the primary vessel.
(a) providing an initial co-solvent based miscella comprising at least one polar solvent, at least one non-polar solvent, solubilized non-Hevea rubber, and solubilized resin;
(b) using a fractionation system comprising multiple fractionators in series to separate
the initial co-solvent based miscella into at least two phases, wherein the multiple
fractionators include a first fractionator, one or more intermediate fractionators,
and a final fractionator, and wherein each fractionator comprises a primary vessel
having (i) a feed inlet, (ii) a side outlet, (iii) a bottom outlet, and (iv) an internal
weir between the interior of the primary vessel and the side outlet or an overflow
vessel external to the primary vessel and fluidly connected to the side outlet;
wherein the initial co-solvent based miscella is fed into the first fractionator primary
vessel through the first fractionator primary vessel feed inlet, and the initial co-solvent
based miscella separates to form (i) a first non-polar solvent viscous rubber phase
in a lower portion of the first fractionator primary vessel and (ii) a first polar
solvent solubilized resin phase above the first non-polar solvent viscous rubber phase,
and wherein a first vapor blanket is maintained above the first polar solvent solubilized
resin phase in an upper portion of the first fractionator primary vessel;
(c) allowing at least a portion of the first polar solvent solubilized resin phase to flow over the internal weir of the first fractionator or into the overflow vessel of the first fractionator for removal from the first fractionator primary vessel through the side outlet;
(d) allowing the first non-polar solvent viscous rubber phase to flow out of the bottom outlet of the first fractionator primary vessel and into an intermediate fractionator;
(e) adding additional polar solvent and optionally additional non-polar solvent to the intermediate fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the first fractionator primary vessel and allowing for separation of that mixture into (i) an intermediate non-polar solvent viscous rubber phase in a lower portion of the intermediate fractionator primary vessel and (ii) an intermediate polar solvent solubilized resin phase above the intermediate non-polar solvent viscous rubber phase, and wherein an intermediate vapor blanket is maintained above the intermediate polar solvent solubilized resin phase in an upper portion of the intermediate fractionator primary vessel;
(f) allowing at least a portion of the intermediate polar solvent solubilized resin phase to flow over the internal weir of the intermediate fractionator or into the overflow vessel of the intermediate fractionator for removal from the intermediate fractionator primary vessel through the side outlet;
(g) allowing the intermediate non-polar solvent viscous rubber phase to flow out of the bottom outlet of the intermediate fractionator primary vessel and into the final fractionator;
(h) adding additional polar solvent and optionally additional non-polar solvent to the final fractionator primary vessel to form a co-solvent based miscella mixture with the non-polar solvent viscous rubber phase from the intermediate fractionator primary vessel and allowing for separation of that mixture into (i) a final non-polar solvent viscous rubber phase in a lower portion of the final fractionator primary vessel and (ii) a final polar solvent solubilized resin phase above the final non-polar solvent viscous rubber phase, and wherein a final vapor blanket is maintained above the final polar solvent solubilized resin phase in an upper portion of the final fractionator primary vessel;
(i) allowing at least a portion of the final polar solvent solubilized resin phase to flow over the internal weir of the final fractionator or into the overflow vessel of the final fractionator for removal from the final fractionator primary vessel; and
(j) allowing the final non-polar solvent viscous rubber phase to flow out of the bottom outlet of the final fractionator primary vessel, thereby providing a separated solubilized rubber phase with reduced resin and polar solvent content as compared to the initial co-solvent based miscella.
the polar solvent solubilized resin phase that is removed from the final fractionator is
fluidly conveyed to the preceding intermediate fractionator, or
the polar solvent solubilized resin phase that is removed from the first fractionator and the first intermediate fractionator is not conveyed to any other fractionator.
the at least one polar solvent comprises acetone, or
the at least one non-polar solvent comprises hexane.
ein Primärgefäß, umfassend:
einen oberen Abschnitt und einen unteren Abschnitt;
einen Zufuhreinlass zum Zuführen einer co-lösungsmittelbasierten Miscella in das Primärgefäß, wobei sich die co-lösungsmittelbasierte Miscella auftrennt, um (i) eine viskose Kautschukphase mit unpolarem Lösungsmittel im unteren Abschnitt des Primärgefäßes und (ii) eine mit einem polaren Lösungsmittel solubilisierte Harzphase über der viskosen Kautschukphase mit unpolarem Lösungsmittel im oberen Abschnitt des Primärgefäßes zu bilden;
einen seitlichen Auslass zum Entfernen der mit einem polaren Lösungsmittel solubilisierten Harzphase aus dem oberen Abschnitt des Primärgefäßes;
ein Überlaufgefäß mit einem Einlass und einem Auslass, wobei der Überlaufgefäßeinlass fluidisch mit dem seitlichen Auslass verbunden ist, sodass die mit einem polaren Lösungsmittel solubilisierte Harzphase durch den seitlichen Auslass in das Überlaufgefäß fließt und durch den Überlaufgefäßauslass entfernt wird; und
einen Bodenauslass zum Entfernen der viskosen Kautschukphase mit unpolarem Lösungsmittel aus dem Primärgefäß.
(a) Bereitstellen einer co-lösungsmittelbasierten Ausgangsmiscella, umfassend mindestens ein polares Lösungsmittel, mindestens ein unpolares Lösungsmittel, einen solubilisierten Nicht-Hevea-Kautschuk und ein solubilisiertes Harz;
(b) Verwenden eines Fraktionierungssystems, das mehrere in Reihe geschaltete Fraktionierer
umfasst, um die co-lösungsmittelbasierte Ausgangsmiscella in mindestens zwei Phasen
aufzutrennen, wobei die mehreren Fraktionierer einen ersten Fraktionierer, einen oder
mehrere Zwischenfraktionierer und einen Endfraktionierer einschließen, und wobei jeder
Fraktionierer ein Primärgefäß mit (i) einem Zufuhreinlass, (ii) einem seitlichen Auslass,
(iii) einem Bodenauslass und (iv) einem internen Überlauf zwischen dem Inneren des
Primärgefäßes und dem seitlichen Auslass oder ein fluidisch mit dem seitlichen Auslass
verbundenes Überlaufgefäß außerhalb des Primärgefäßes umfasst;
wobei die co-lösungsmittelbasierte Ausgangsmiscella dem ersten Fraktionierer-Primärgefäß
durch den Zufuhreinlass des ersten Fraktionierer-Primärgefäßes zugeführt wird und
die co-lösungsmittelbasierte Ausgangsmiscella trennt, um (i) eine erste viskose Kautschukphase
mit unpolarem Lösungsmittel in einem unteren Abschnitt des ersten Fraktionierer-Primärgefäßes
und (ii) eine erste mit unpolarem Lösungsmittel solubilisierte Harzphase über der
ersten viskosen Kautschukphase mit unpolarem Lösungsmittel zu bilden, und wobei eine
erste Dampfdecke über der ersten mit polarem Lösungsmittel solubilisierten Harzphase
in einem oberen Abschnitt des ersten Fraktionierer-Primärgefäßes gehalten wird;
(c) Ermöglichen, dass mindestens ein Abschnitt der mit einem polaren Lösungsmittel solubilisierten Harzphase über den internen Überlauf des ersten Fraktionierers oder in das Überlaufgefäß des ersten Fraktionierers zum Entfernen aus dem ersten Fraktionierer-Primärgefäß durch den seitlichen Auslass fließt;
(d) Ermöglichen, dass die erste viskose Kautschukphase mit einem unpolaren Lösungsmittel aus dem Bodenauslass des ersten Fraktionierer-Primärgefäßes und in einen Zwischenfraktionierer austritt;
(e) Hinzufügen eines zusätzlichen polaren Lösungsmittels und gegebenenfalls eines zusätzlichen nichtpolaren Lösungsmittels zu dem Zwischenfraktionierer-Primärgefäß, um eine co-lösungsmittelbasierte Miscellamischung mit der viskosen Kautschukphase mit unpolarem Lösungsmittel aus dem ersten Fraktionierer-Primärgefäß zu bilden und eine Trennung dieser Mischung in (i) eine viskose Zwischenkautschukphase mit unpolarem Lösungsmittel in einem unteren Abschnitt des Zwischenfraktionierer-Primärgefäßes und (ii) eine mit einem polaren Lösungsmittel solubilisierte Zwischenharzphase über der viskosen Zwischenkautschukphase mit unpolarem Lösungsmittel zu ermöglichen, und wobei eine Zwischendampfdecke über der mit einem polaren Lösungsmittel solubilisierten Zwischenharzphase in einem oberen Abschnitt des Zwischenfraktionierer-Primärgefäßes gehalten wird;
(f) Ermöglichen, dass mindestens ein Abschnitt der mit einem polaren Lösungsmittel solubilisierten Zwischenharzphase über den internen Überlauf des Zwischenfraktionierers oder in das Überlaufgefäß des Zwischenfraktionierers zum Entfernen aus dem Zwischenfraktionierer-Primärgefäß durch den seitlichen Auslass fließt;
(g) Ausströmenlassen der viskosen Zwischenkautschukphase mit unpolarem Lösungsmittel aus dem Bodenauslass des Zwischenfraktionierer-Primärgefäßes und in den Endfraktionierer;
(h) Hinzufügen eines zusätzlichen polaren Lösungsmittels und gegebenenfalls eines zusätzlichen nichtpolaren Lösungsmittels zum Endfraktionierer-Primärgefäß, um eine co-lösungsmittelbasierte Miscellamischung mit der viskosen Kautschukphase mit nichtpolarem Lösungsmittel aus dem Zwischenfraktionierer-Primärgefäß zu bilden und eine Trennung dieser Mischung in (i) eine viskose Endkautschukphase mit nichtpolarem Lösungsmittel in einem unteren Abschnitt des Endfraktionierer-Primärgefäßes und (ii) eine mit polarem Lösungsmittel solubilisierte Endharzphase über der viskosen Endkautschukphase mit Lösungsmittel zu ermöglichen, und wobei eine endgültige Dampfdecke über der mit polarem Lösungsmittel solubilisierten Endharzphase in einem oberen Abschnitt des Endfraktionierer-Primärgefäßes gehalten wird;
(i) Ermöglichen, dass mindestens ein Abschnitt der mit einem polaren Lösungsmittel solubiliserten Endharzphase über den internen Überlauf des Endfraktionierers oder in das Überlaufgefäß des Endfraktionierers zum Entfernen aus dem Endfraktionierer-Primärgefäß fließt; und
(j) Ermöglichen, dass die viskose Endkautschukphase mit unpolarem Lösungsmittel aus dem Bodenauslass des primären Endfraktionnierer-Primärgefäßes austritt, wodurch eine aufgetrennte solubilisierte Kautschukphase mit reduziertem Gehalt an Harz und polarem Lösungsmittel im Vergleich zu der co-lösungsmittelbasierten Ausgangsmiscella bereitgestellt wird.
die mit einem polarem Lösemittel solubilisierte Harzphase, die aus dem Endfraktionierer entfernt wird, wird fluidisch zu dem vorhergehenden Zwischenfraktionierer gefördert, oder
die mit einem polarem Lösemittel solubilisierte Harzphase, die aus dem ersten Fraktionierer und dem ersten Zwischenfraktionierer entfernt wird, wird nicht zu einem anderen Fraktionierer gefördert.
das mindestens eine polare Lösungsmittel umfasst Aceton, oder
das mindestens eine unpolare Lösungsmittel umfasst Hexan.
une cuve primaire comprenant :
une partie supérieure et une partie inférieure ;
une entrée d'alimentation pour alimenter un miscella à base de cosolvant dans la cuve primaire, dans lequel le miscella à base de cosolvant se sépare pour former (i) une phase caoutchouc visqueuse de solvant apolaire dans la partie inférieure de la cuve primaire et (ii) une phase résine solubilisée de solvant polaire au-dessus de la phase caoutchouc visqueuse de solvant apolaire dans la partie supérieure de la cuve primaire ;
une sortie latérale pour retirer la phase résine solubilisée de solvant polaire de la partie supérieure de la cuve primaire ;
une cuve de trop-plein ayant une entrée et une sortie, dans lequel l'entrée de cuve de trop-plein est reliée de manière fluide à la sortie latérale de telle sorte que la phase résine solubilisée de solvant polaire s'écoule à travers la sortie latérale dans la cuve de trop-plein et est retirée par l'intermédiaire de la sortie de cuve de trop-plein ; et
une sortie inférieure pour retirer la phase caoutchouc visqueuse de solvant apolaire de la cuve primaire.
(a) la fourniture d'un miscella à base de cosolvant initial comprenant au moins un solvant polaire, au moins un solvant apolaire, du caoutchouc non-Hevea solubilisé, et une résine solubilisée ;
(b) l'utilisation d'un système de fractionnement comprenant de multiples fractionnateurs
en série pour séparer le miscella à base de cosolvant initial en au moins deux phases,
dans lequel les multiples fractionnateurs incluent un premier fractionnateur, un ou
plusieurs fractionnateurs intermédiaires et un fractionnateur final, et dans lequel
chaque fractionnateur comprend une cuve primaire ayant (i) une entrée d'alimentation,
(ii) une sortie latérale, (iii) une sortie inférieure, et (iv) un barrage interne
entre l'intérieur de la cuve primaire et la sortie latérale ou une cuve de trop-plein
externe à la cuve primaire et en communication fluidique avec la sortie latérale ;
dans lequel le miscella à base de cosolvant initial est alimenté dans la cuve primaire
de premier fractionnateur par l'intermédiaire de l'entrée d'alimentation de cuve primaire
de premier fractionnateur, et le miscella à base de cosolvant initial se sépare pour
former (i) une première phase caoutchouc visqueuse de solvant apolaire dans une partie
inférieure de la cuve primaire de premier fractionnateur et (ii) une première phase
résine solubilisée de solvant polaire au-dessus de la première phase caoutchouc visqueuse
de solvant apolaire, et dans lequel une première couverture de vapeur est maintenue
au-dessus de la première phase résine solubilisée de solvant polaire dans une partie
supérieure de la cuve primaire de premier fractionnateur ;
(c) le fait de permettre à au moins une partie de la première phase résine solubilisée de solvant polaire de s'écouler par-dessus le barrage interne du premier fractionnateur ou dans la cuve de trop-plein du premier fractionnateur pour un retrait hors de la cuve primaire de premier fractionnateur par l'intermédiaire de la sortie latérale ;
(d) le fait de permettre à la première phase caoutchouc visqueuse de solvant apolaire de s'écouler à l'extérieur de la sortie inférieure de la cuve primaire de premier fractionnateur et dans un fractionnateur intermédiaire ;
(e) l'ajout de solvant polaire supplémentaire et éventuellement de solvant apolaire supplémentaire à la cuve primaire de fractionnateur intermédiaire pour former un mélange de miscella à base de cosolvant avec la phase caoutchouc visqueuse de solvant apolaire provenant de la cuve primaire de premier fractionnateur et le fait de permettre la séparation de ce mélange en (i) une phase caoutchouc visqueuse de solvant apolaire intermédiaire dans une partie inférieure de la cuve primaire de fractionnateur intermédiaire et (ii) une phase résine solubilisée de solvant polaire intermédiaire au-dessus de la phase caoutchouc visqueuse de solvant apolaire intermédiaire, et dans lequel une couverture de vapeur intermédiaire est maintenue au-dessus de la phase résine solubilisée de solvant polaire intermédiaire dans une partie supérieure de la cuve primaire de fractionnateur intermédiaire ;
(f) le fait de permettre à au moins une partie de la phase résine solubilisée de solvant polaire intermédiaire de s'écouler par-dessus le barrage interne du fractionnateur intermédiaire ou dans la cuve de trop-plein du fractionnateur intermédiaire pour un retrait hors de la cuve primaire de fractionnateur intermédiaire par l'intermédiaire de la sortie latérale ;
(g) le fait de permettre à la phase caoutchouc visqueuse de solvant apolaire intermédiaire de s'écouler à l'extérieur de la sortie inférieure de la cuve primaire de fractionnateur intermédiaire et dans le fractionnateur final ;
(h) l'ajout de solvant polaire supplémentaire et éventuellement de solvant apolaire supplémentaire à la cuve primaire de fractionnateur final pour former un mélange de miscella à base de cosolvant avec la phase caoutchouc visqueuse de solvant apolaire provenant de la cuve primaire de fractionnateur intermédiaire et le fait de permettre la séparation de ce mélange en (i) une phase caoutchouc visqueuse de solvant apolaire finale dans une partie inférieure de la cuve primaire de fractionnateur final et (ii) une phase résine solubilisée de solvant polaire finale au-dessus de la phase caoutchouc visqueuse de solvant apolaire finale, et dans lequel une couverture de vapeur finale est maintenue au-dessus de la phase résine solubilisée de solvant polaire finale dans une partie supérieure de la cuve primaire de fractionnateur final ;
(i) le fait de permettre à au moins une partie de la phase résine solubilisée de solvant polaire finale de s'écouler par-dessus le barrage interne du fractionnateur final ou dans la cuve de trop-plein du fractionnateur final pour un retrait hors de la cuve primaire de fractionnateur final ; et
(j) le fait de permettre à la phase caoutchouc visqueuse de solvant apolaire finale de s'écouler à l'extérieur de la sortie inférieure de la cuve primaire de fractionnateur final, en fournissant de ce fait une phase caoutchouc solubilisé séparée avec des teneurs réduites en résine et en solvant polaire par comparaison avec le miscella à base de cosolvant initial.
la phase résine solubilisée de solvant polaire qui est retirée du fractionnateur final est acheminée de manière fluide vers le fractionnateur intermédiaire qui précède, ou
la phase résine solubilisée de solvant polaire qui est retirée du premier fractionnateur et du premier fractionnateur intermédiaire n'est pas acheminée vers l'un quelconque autre fractionnateur.
l'au moins un solvant polaire comprend de l'acétone, ou
l'au moins un solvant apolaire comprend de l'hexane.
REFERENCES CITED IN THE DESCRIPTION
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.
Non-patent literature cited in the description
- BRYAN A. GARNERA Dictionary of Modern Legal Usage 62419950000 [0056]